Okay, here’s the long, cozy version I like to give friends who want a map of Holmes’s literary hangouts.
Arthur Conan Doyle wrote four full-length novels that star Sherlock Holmes: 'A Study in Scarlet' (his debut), 'The Sign of the Four', 'The Hound of the Baskervilles', and 'The Valley of Fear'. Those are the big, book-length mysteries where plots stretch out, villains get more room, and you feel the weight of the investigation.
Beyond the novels, Doyle published fifty-six short stories collected into five main volumes: 'The Adventures of Sherlock Holmes', 'The Memoirs of Sherlock Holmes', 'The Return of Sherlock Holmes', 'His Last Bow', and 'The Case-Book of Sherlock Holmes'. Many of the best-known snippets—'The Speckled Band', 'A Scandal in Bohemia', 'The Final Problem', 'The Adventure of the Empty House'—live in those collections. If you're hunting for a particular case, look for the title beginning 'The Adventure of...' Most modern editions gather these novels and collections together, but I like to read a novel, then a few short stories, so the pacing stays lively. Curl up with 'A Study in Scarlet' to meet Holmes, then jump into 'The Adventures' for a parade of brilliant little deductions—it's perfect if you want to taste the variety without committing to two-hundred-plus pages every time.